Patents by Inventor Gary Chang-Feng Wu

Gary Chang-Feng Wu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5251305
    Abstract: An apparatus for preventing bus contention among a plurality of data sources is described which creates signals to be used to disable two of three data sources which share a common bus immediately prior to a bus access cycle. The circuit employs a negative edge triggered flip-flop. This flip-flop generates disable signals which are shifted in phase by 90.degree. with respect to the bus access clock signal. These signals are active one-quarter of a clock cycle before a new bus cycle begins. The early disable serves to clear the bus for access by substantially eliminating the possibility that a slowly responding disabled data source is still active while a quickly responding enabled data source has just become active. The early disabling of the data signals does not result in loss of data. When all data sources on the bus are turned off, a high signal simply goes higher and a low signal rises slowly.
    Type: Grant
    Filed: April 4, 1991
    Date of Patent: October 5, 1993
    Assignee: Unisys Corporation
    Inventors: Philip A. Murphy, Jr., Wayne A. Genetti, Gunnar K. Gunnarsson, Edward J. Pullin, Gary Chang-Feng Wu